Comparative Dosing of Metoprolol and Nadolol for Beta-Blockade
Based on current guidelines, metoprolol is typically dosed at 50-200 mg twice daily (tartrate) or 50-200 mg once daily (succinate), while nadolol is dosed at 40-120 mg once daily for patients requiring beta-blockade. 1
Dosage Comparison Table
| Beta-Blocker | Selectivity | Daily Dosage Range | Frequency | Maximum Daily Dose |
|---|---|---|---|---|
| Metoprolol tartrate | Beta-1 | 100-400 mg | Twice daily | 400 mg |
| Metoprolol succinate | Beta-1 | 50-200 mg | Once daily | 400 mg |
| Nadolol | Non-selective | 40-120 mg | Once daily | 320 mg |
Key Differences
Pharmacological Properties
- Metoprolol: Beta-1 selective blocker, which primarily affects cardiac receptors with less effect on bronchial and vascular beta-2 receptors 1
- Nadolol: Non-selective beta blocker that affects both beta-1 and beta-2 receptors 1
Administration Frequency
- Metoprolol tartrate: Requires twice-daily dosing due to shorter half-life 1
- Metoprolol succinate: Extended-release formulation allows once-daily dosing 1
- Nadolol: Longer half-life allows for once-daily dosing 1
Dosing Considerations
Metoprolol
- Starting dose typically 25-50 mg twice daily for tartrate formulation 1
- For extended-release (succinate), starting dose is usually 50 mg once daily 1
- Titrate upward as needed and tolerated
- Maximum daily dose is 400 mg for both formulations 1
Nadolol
- Starting dose typically 40 mg once daily 1
- Titrate upward as needed and tolerated
- Maximum daily dose is 320 mg 1
- Requires dose reduction in renal impairment 1
Clinical Applications and Precautions
Indications where either agent may be used:
- Hypertension
- Angina pectoris
- Atrial fibrillation (rate control)
- Post-myocardial infarction
Specific Considerations:
- Respiratory disease: Metoprolol is preferred over nadolol in patients with reactive airway disease due to its beta-1 selectivity 1
- Renal impairment: Nadolol requires dose adjustment in renal dysfunction 1
- Frequency preference: Nadolol may offer better adherence with once-daily dosing 1
Common Precautions for Both:
- Avoid abrupt cessation of either medication 1
- Use caution in patients with:
- AV block greater than first degree
- Sinus node dysfunction
- Decompensated heart failure
- Cardiogenic shock
- Hypotension
Potency Comparison
Based on comparative studies, nadolol demonstrates greater potency than metoprolol, with the following approximate equivalence 2:
- Nadolol 40 mg ≈ Metoprolol 100-120 mg
This higher potency of nadolol should be considered when switching between these medications to maintain equivalent beta-blockade.